Dr. Kay Scarpetta, the spunky and thoughtful chief medical examiner introduced in Cornwell's first novel, Postmortem , makes her second commanding appearance here. Beryl Madison, a writer of historical romances, is grotesquely slashed to death in her Richmond, Va., home after returning from Key West, where she had fled, terrified by threats to her life. Why Madison let the killer into her home is Scarpetta's first question; pursuing its answer involves her in the murder of another writer, reclusive Cary Harper, who was Madison's jealous mentor; the suicide of Harper's sister; the FBI investigation of Madison's crooked lawyer; and, along with bewildering threats to her own life, plenty of complex, satisfying forensic sleuthing. Finding clues under a microscope, in the records of a psychiatric hospital, at a Key West restaurant and in a terrorist skyjacking, Scarpetta follows a trail of evidence--clues that would lead nowhere without her intelligence, compassion and imagination--to a powerful conclusion. Cornwell handles her heroine's interactions with the local police and a former lover with authority to equal her technological expertise. Mystery Guild main selection; Literary Guild alternate. (Feb.)